A system that provides a rotating shaft output can be classified by speed, power, and torque. Although these measures are related in some ways, the concept of torque may be more closely aligned with the experience of the user is operating such a machine. However, in certain environments, it is traditionally difficult to control torque accurately due to due to the slow frequency response and non-linear behavior of the transmission.
While simple PID control schemes may be used, such systems will generally not be able accurately control the output torque of the transmission. This is primarily due to the control lag, and may result in oscillation, instability, and a generally poor user experience. Although the application of gains can speed response time, it may also result in instability and over-control. In particular, while inadequate gains will not be sufficient to alleviate the lag problem, excessive gains may cause control ringing or under-damped oscillation.
It will be appreciated that this background description has been created by the inventors to aid the reader, and represents concepts known to the inventors. It is not a discussion of, nor reference to, prior art, nor is this section intended to imply that any of the indicated problems were themselves appreciated in the art. While the principles described herein can, in some regards and embodiments, avoid the problems described, it will be appreciated that the scope of the protected innovation is defined by the attached claims, and not by the ability of the claimed invention to solve any specific problem noted herein.